Bruce Cree, MD, PhD, MAS, Associate Professor of Clinical Neurology in the Department of Neurology at the University of California San Francisco, discusses post-hoc analysis data of newly presenting neuromyelitis optica spectrum disorder (NMOSD) patients from the N-MOmentum trial (NCT02200770) of inebilizumab. These results were presented at the 2022 AAN Annual Meeting.

NMOSD is a rare central nervous disorder that primarily affects the spinal cord and optic nerves. Symptoms of NMOSD may include blindness in one or both eyes, weakness or paralysis of arms or legs, spasming, loss of sensation, uncontrollable vomiting and hiccups, and bladder/bowel problems due to spinal cord damage.

As Dr. Cree explains, N-MOmentum was a phase 2/3, double-blind trial with a 28-week randomized, placebo-controlled period and an open-label extension of ≥2 years. Post-hoc analyses were conducted for participants with AQP4+ NMOSD who were enrolled after their first attack. Participants received intravenous inebilizumab 300 mg or placebo on day 1, day 15 and every 26 weeks thereafter. Except for oral corticosteroids during the first 2 weeks with a 1-week taper, no immunosuppressants were used. The primary endpoint of the study was time to first adjudicated attack. Disability was assessed as a secondary endpoint via the Expanded Disability Status Scale (EDSS). 

Of the 37 participants enrolled after their first attack, 1/24 inebilizumab-treated (4.2%) and 3/13 placebo-treated participants (23.1%) had an adjudicated attack. By comparison, of the 176 participants with two or more pre-study attacks, 17/137 inebilizumab-treated (12.4%) and 19/39 placebo-treated participants (48.7%) had an adjudicated attack.  Among those with 1 pre-study attack, EDSS worsening from baseline was observed in 3/24 inebilizumab-treated (12.5%) and 3/13 placebo-treated participants (23.1%;), compared with 21/137 inebilizumab-treated (15.3%) and 15/39 placebo-treated (38.5%) participants with two or more pre-study attacks. No significant differences in attacks or EDSS worsening were found between participants with 1 pre-study attack and those with ≥2 pre-study attacks. Treatment-emergent adverse events were reported for 19/24 inebilizumab-treated (79.2%) and 10/13 placebo-treated participants (76.9%) with 1 pre-study attack. 

As Dr. Cree stresses, although no confirmed cases of hypogammaglobulinemia were identified in inebilizumab clinical trials, it is a likely side effect of the drug that clinicians should be aware of. Overall, this post-hoc analysis data demonstrates that the safety and efficacy of inebilizumab in AQP4+ adults with newly presenting NMOSD (1 pre-study attack) were similar to those in participants with a history of two or more pre-study attacks.

To learn more about NMOSD and other neurological disorders, visit https://checkrare.com/diseases/neurology-nervous-system-diseases/